Robotic surgical assemblies and instrument drive connectors thereof

ABSTRACT

An instrument drive connector includes a housing assembly, an elongated shaft extending distally from the housing assembly, and a first drive assembly at least partially disposed within the housing assembly and the elongated shaft. The first drive assembly includes a first drive screw, a first input drive coupler non-rotatably coupled to a proximal end of the first drive screw, a first drive nut threadedly engaged with a threaded body portion of the first drive screw and longitudinally movable relative thereto in response to rotation of the first drive screw, and a locking link. The locking link includes an elongated body having a proximal end portion coupled to the first drive nut and longitudinally movable relative thereto between a proximal non-locking position and a distal locking position, and a distal end portion including a switch actuation assembly including a switch actuating arm biased towards the distal locking position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Application filed under 35 U.S.C. § 371(a) of International Patent Application Serial No. PCT/US2016/052783, filed Sep. 21, 2016, which claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 62/232,640, filed Sep. 25, 2015, the entire disclosure of which is incorporated by reference herein.

BACKGROUND

Robotic surgical systems have been used in minimally invasive medical procedures. Some robotic surgical systems included a console supporting a robot arm and a surgical instrument, having at least one end effector (e.g., a forceps or a grasping tool), mounted to the robot arm. The robotic arm provided mechanical power to the surgical instrument for its operation and movement.

Robotic surgical systems supported surgical instruments that were configured to couple to a variety of types of end effectors by enabling these end effectors to be readily exchanged during a surgical procedure. Typically, this exchange of end effectors was performed by manually detaching the end effector from the remainder of the surgical instrument without detaching the instrument drive unit from the surgical instrument. This often meant that end effectors could be detached from the surgical instrument by a clinician inadvertently by hitting the wrong button or switch.

SUMMARY

The present disclosure is directed to surgical instruments having an instrument drive connector that is releasably coupled to an end effector and that reduces the likelihood of inadvertent removal of the end effector from a surgical instrument during the end effector exchange process.

In one aspect of the present disclosure, an instrument drive connector for interconnecting an instrument drive unit and an end effector, wherein the instrument drive connector transmits at least one force from the instrument drive unit to the end effector to effect a function of the end effector, includes a housing assembly, an elongated shaft extending distally from the housing assembly, and a first drive assembly at least partially disposed within the housing assembly and the elongated shaft. The first drive assembly includes a first drive screw having a proximal end and a distal end, a first input drive coupler non-rotatably coupled to the proximal end of the first drive screw, a first drive nut threadedly engaged with a threaded body portion of the first drive screw and longitudinally movable relative thereto in response to rotation of the first drive screw, and a locking link. The locking link includes an elongated body having a proximal end portion and a distal end portion, the proximal end portion is coupled to the first drive nut and longitudinally movable relative thereto between a proximal non-locking position and a distal locking position, and the distal end portion includes a switch actuation assembly including a switch actuating arm biased towards the distal locking position.

In embodiments, the switch actuation assembly includes a coil spring disposed in an elongated opening proximal of the switch actuating arm. The coil spring biases the switch actuating arm towards the distal locking position and is movable to the proximal non-locking position.

The instrument drive connector may include a switch disposed in the elongated shaft. In some embodiments, the instrument drive connector includes an annular member disposed in a distal end of the elongated shaft. The annular member may include a pair of electrical contacts electrically coupled to the switch.

A flex circuit may be disposed in the elongated shaft, and the switch may be disposed at a distal end of the flex circuit. In some embodiments, the flex circuit extends longitudinally through the elongated shaft, and includes a proximal end configured for electrical communication with a processor.

The proximal end portion of the locking link may include a longitudinal slot formed therein, and the first drive nut may have a rod disposed within the longitudinal slot of the locking link such that when the first drive nut is in the distal locking position, the rod of the first drive nut is engaged with a distal end surface of the longitudinal slot, and when the first drive nut is in the proximal non-locking position, the rod of the first drive nut is disposed adjacent a proximal end surface of the longitudinal slot.

In embodiments, the housing assembly defines an aperture in a side surface thereof, and the first drive nut includes a tab extending through the aperture and into a finger switch for manual movement of the first drive nut.

The instrument drive connector may include a second drive assembly. The second drive assembly may include a second drive screw having a proximal end and a distal end, a second input drive coupler non-rotatably coupled to the proximal end of the second drive screw, a second drive nut threadedly engaged with a threaded body portion of the second drive screw and longitudinally movable relative thereto in response to rotation of the second drive screw, and an articulation link. The articulation link may include an elongated body having a proximal end and a distal end, the proximal end fixedly coupled to the second drive nut such that longitudinal translation of the second drive nut causes longitudinal translation of the articulation link.

The instrument drive connector may include a third drive assembly. The third drive assembly may include a proximal shaft, a distal shaft, a drive rod, and a drive shaft. The proximal shaft may include a third input drive coupler non-rotatably secured to a proximal end of the proximal shaft and a distal gear non-rotatably secured to a distal end of the proximal shaft. The distal shaft may include a proximal gear non-rotatably secured thereto and meshingly engaged with the distal gear of the proximal shaft. The drive rod may include a threaded elongated body engaged with a threaded channel defined in the distal shaft and is longitudinally movable relative thereto in response to rotation of the distal shaft. The drive shaft may be coupled to a distal end of the drive rod and may be longitudinally movable therewith.

In another aspect of the present disclosure, a surgical instrument for use with and for selective connection to an instrument drive unit, includes an instrument drive connector and a surgical loading unit. The instrument drive connector includes a housing assembly and an elongated shaft, and a first drive assembly at least partially disposed within the housing assembly and the elongated shaft. The first drive assembly includes a first drive screw having a proximal end and a distal end, a first input drive coupler non-rotatably coupled to the proximal end of the first drive screw, a first drive nut threadedly engaged with a threaded body portion of the first drive screw and longitudinally movable relative thereto in response to rotation of the first drive screw, and a locking link. The locking link includes an elongated body having a proximal end portion and a distal end portion, the proximal end portion is coupled to the first drive nut and longitudinally movable relative thereto between a proximal non-locking position and a distal locking position, and the distal end portion includes a switch actuation assembly including a switch actuating arm biased towards the distal locking position. The surgical loading unit is selectively attachable to the instrument drive connector and includes an end effector. When the locking link of the first drive assembly is in the proximal non-locking position, the surgical loading unit can be inserted or removed from the instrument drive connector, and when the locking link is in the distal locking position, the surgical loading unit cannot be either inserted or removed from instrument drive connector.

In embodiments, the switch actuation assembly of the locking link of the first drive assembly includes a coil spring disposed in an elongated opening proximal of the switch actuating arm. The coil spring biases the switch actuating arm towards the distal locking position and is movable to the proximal non-locking position.

The instrument drive connector may include a switch disposed in the elongated shaft. In some embodiments, the instrument drive connector includes an annular member disposed in a distal end of the elongated shaft. The annular member may include a pair of electrical contacts electrically coupled to the switch.

The instrument drive connector may include a flex circuit disposed in the elongated shaft, and the switch may be disposed at a distal end of the flex circuit. In some embodiments, the flex circuit extends longitudinally through the elongated shaft of the instrument drive connector, and includes a proximal end configured for electrical communication with a processor.

The proximal end portion of the locking link may include a longitudinal slot formed therein, and the first drive nut may have a rod disposed within the longitudinal slot of the locking link such that when the first drive nut is in the distal locking position, the rod of the first drive nut is engaged with a distal end surface of the longitudinal slot, and when the first drive nut is in the proximal non-locking position, the rod of the first drive nut is disposed adjacent a proximal end surface of the longitudinal slot.

In embodiments, the housing assembly of the instrument drive connector defines an aperture in a side surface thereof, and the first drive nut includes a tab extending through the aperture and into a finger switch for manual movement of the first drive nut.

The instrument drive connector may include a second drive assembly. The second drive assembly may include a second drive screw having a proximal end and a distal end, a second input drive coupler non-rotatably coupled to the proximal end of the second drive screw, a second drive nut threadedly engaged with a threaded body portion of the second drive screw and longitudinally movable relative thereto in response to rotation of the second drive screw, and an articulation link. The articulation link may include an elongated body having a proximal end and a distal end, the proximal end fixedly coupled to the second drive nut such that longitudinal translation of the second drive nut causes longitudinal translation of the articulation link. The distal end of the articulation link may be releasably coupled to the surgical loading unit to effect articulation of the end effector.

The instrument drive connector may include a third drive assembly including a proximal shaft, a distal shaft, a drive rod, and a drive shaft. The proximal shaft may include a third input drive coupler non-rotatably secured to a proximal end of the proximal shaft and a distal gear non-rotatably secured to a distal end of the proximal shaft. The distal shaft may include a proximal gear non-rotatably secured thereto and meshingly engaged with the distal gear of the proximal shaft. The drive rod may include a threaded elongated body engaged with a threaded channel defined in the distal shaft and longitudinally movable relative thereto in response to rotation of the distal shaft. The drive shaft may be coupled to a distal end of the drive rod and is longitudinally movable therewith. A distal end of the drive shaft may be in operable communication with the surgical loading unit to effect a function of the end effector.

Other aspects, features, and advantages will be apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, and in which corresponding reference characters indicate corresponding parts in each of the several views, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein:

FIG. 1 is a schematic illustration of a robotic surgical system in accordance with the present disclosure;

FIG. 2 is a perspective view of a surgical assembly of the robotic surgical system of FIG. 1;

FIG. 3 is a perspective view of an instrument drive connector of the surgical assembly of FIG. 2;

FIG. 4 is an enlarged perspective view of a housing assembly of the instrument drive connector of FIG. 3;

FIG. 5 is another enlarged perspective view of the housing assembly of the instrument drive connector of FIGS. 3 and 4;

FIG. 6 is a cross-sectional view of the instrument drive connector of FIGS. 3-5, taken along line 6-6 of FIG. 5;

FIG. 7 is a cross-sectional view of the instrument drive connector of FIGS. 3-6, taken along line 7-7 of FIG. 4;

FIG. 8 is a cross-sectional view of the instrument drive connector of FIGS. 3-7, taken along line 8-8 of FIG. 6;

FIG. 9A is a cross-sectional view of the instrument drive connector of FIGS. 3-8, taken along line 6-6 of FIG. 5, illustrating a first drive nut of the instrument drive connector in a locking position;

FIG. 9B is a cross-sectional view of the instrument drive connector of FIGS. 3-9A, taken along line 6-6 of FIG. 5, illustrating a first drive nut of the instrument drive connector in a non-locking position;

FIG. 10 is a perspective view, with parts removed, of internal components of the instrument drive connector of FIGS. 3-9B;

FIG. 11 is a cross-sectional view of the instrument drive connector of FIGS. 3-10, taken along line 11-11 of FIG. 7;

FIG. 12 is a cross-sectional view of the instrument drive connector of FIGS. 3-11, taken along line 12-12 of FIG. 7;

FIG. 13 is a perspective view, with parts removed, of internal components of the instrument drive connector of FIGS. 3-12;

FIG. 14 is an enlarged view of the area of detail indicated in FIG. 13;

FIG. 15 is an enlarged perspective view, with parts removed, of the internal components of the instrument drive connector of FIG. 14; and

FIG. 16 is a perspective view of an annular member of instrument drive connector of FIG. 15.

DETAILED DESCRIPTION

In this disclosure, the term “distal” refers to a portion of a structure that is farther from a clinician, while the term “proximal” refers to a portion of the same structure that is closer to the clinician. As used herein, the term “subject” refers to a human patient or other animal. The term “clinician” refers to a doctor (e.g., a surgeon), nurse, or other care provider, and may include support personnel.

Referring initially to FIG. 1, a robotic surgical system, such as, for example, medical work station 1, generally includes a plurality of robot arms 2 and 3, a control device 4, and an operating console 5 coupled with control device 4. Operating console 5 includes a display device 6, which is set up in particular to display three-dimensional images, and manual input devices 7 and 8, by means of which a clinician (not shown), for example a surgeon, is able to telemanipulate robot arms 2 and 3 in a first operating mode, as known in principle to a person skilled in the art.

Each of the robot arms 2 and 3 includes a plurality of members, which are connected through joints, to which may be releasably attached, for example, a surgical assembly 10. Robot arms 2 and 3 may be driven by electric drives (not shown) that are connected to control device 4. Control device 4 (e.g., a computer) is set up to activate the drives, in particular by means of a computer program, in such a way that robot arms 2 and 3 and/or surgical assembly 10 execute a desired movement according to a movement defined by means of manual input devices 7 and 8. Control device 4 may also be set up in such a way that it regulates the movement of robot arms 2 and 3 and/or of the drives (not shown). Control device 4 may control a plurality of motors, e.g., “Motor 1 . . . n,” with each motor configured to drive movement of robotic arms 2 and 3 in a plurality of directions.

Medical work station 1 is configured for use on a patient “P” lying on a patient table “ST” to be treated in a minimally invasive manner by means of a surgical instrument 100 of surgical assembly 10. Medical work station 1 may also include more than two robot arms 2 and 3, the additional robot arms likewise being connected to control device 4 and being telemanipulatable by means of operating console 5. A surgical assembly 10, may also be attached to the additional robot arm. Medical work station 1 may include a database 9, in particular coupled to with control device 4, in which are stored for example pre-operative data from patient “P” and/or anatomical atlases.

Reference may be made to U.S. Patent Publication No. 2012/0116416, filed on Nov. 3, 2011, entitled “Medical Workstation,” the entire content of which is incorporated herein by reference, for a detailed discussion of the construction and operation of medical work station 1.

Turning now to FIG. 2, surgical assembly 10 is shown coupled with or to robotic arm 2 via a rail, track, or slide 12. While surgical assembly 10 is discussed singularly, a person of ordinary skill in the art can readily appreciate that the medical work station 1 may also include a plurality of substantially identical surgical assemblies 10 coupled with or to each of the robotic arms 2 and 3 (FIG. 1). Surgical assembly 10 includes an instrument drive unit 50 coupled to an adapter or instrument drive connector 200 of surgical instrument 100 having a surgical loading unit 400 including an end effector 410 disposed at a distal end thereof.

Instrument drive unit 50 of surgical assembly 10 may be supported on or connected to a slider 11 that is movably connected to a track 12 of robotic arm 2. Slider 11 moves, slides, or translates along a longitudinal axis “Y” defined by track 12 of surgical robotic arm 2 upon a selective actuation by motors (not shown) disposed in track 12 of robotic arm 2 or motors (e.g., one or more of “Motor 1 . . . n”) of control device 4. As such, slider 11, with surgical assembly 10 connected thereto, can be moved to a selected position along track 12 of robotic arm 2.

Instrument drive unit 50 includes a housing 60 having a proximal end 62 and a distal end 64 configured to be operably coupled to instrument drive connector 200 of surgical instrument 100. Housing 60 of instrument drive unit 50 houses a plurality of motors (not shown) that are configured to power surgical instrument 100, for example, to drive various operations of end effector 410 of surgical instrument 100. Each motor of instrument drive unit 50 includes an output drive coupler (not shown) attached thereto such that the drive couplers are independently rotatable with respect to one another. Drive couplers are disposed at distal end 64 of housing 60 of instrument drive unit 50 and are at least partially exposed for engagement with drive assemblies of instrument drive connector 200. Thus, in use, instrument drive unit 50 transfers power and actuation forces from its motors to instrument drive connector 200 of surgical instrument 100 via rotation of the output drive couplers to ultimately drive movement of components of end effector 410 of surgical instrument 100, as described in further detail below.

Control device 4 (FIG. 1) may control the motors of instrument drive unit 50. In some embodiments, one or more motors may receive signals wirelessly (e.g., from control device 4). It is contemplated that control device 4 coordinates the activation of the various motors (“Motor 1 . . . n”), and the motors of instrument drive unit 50, to coordinate an operation and/or movement of surgical instrument 100.

Surgical loading unit 400 is selectively attachable to instrument drive connector 200 and includes an elongate portion 402 and an end effector 410. Surgical loading unit 400 may be a single use loading unit that is disposable, or a multiple use loading unit that can be sterilized for reuse. Elongate portion 402 of surgical loading unit 400 may be tubular and has a proximal end 402 a configured to be coupled to a distal cap 222 of an elongated shaft 220 of instrument drive connector 200. Proximal end 402 a of elongate portion 402 has a protrusion or lug (not shown) extending laterally therefrom that is configured to be axially passed through distal cap 222 of elongated shaft 220 of instrument drive connector 200 and rotated to selectively lockingly couple surgical loading unit 400 with instrument drive connector 200. Elongate portion 402 of surgical loading unit 400 has a distal end 402 b having end effector 410 attached thereto. End effector 410 generally includes a pair of opposing jaw members 412 a and 412 b, and may include a staple cartridge, knife blade, among other fastening, cutting, clamping elements within the purview of those skilled in the art. It is contemplated that end effector 410 may be directly coupled to instrument drive connector 200 rather than be directly coupled to elongate portion 402 of surgical loading unit 400.

Referring now to FIGS. 3-5, instrument drive connector 200 of surgical instrument 100 includes a housing assembly 210 and an elongated shaft 220 extending distally from the housing assembly 210 and terminating at a distal cap 222. Housing assembly 210 includes, from proximal to distal, a top or proximal housing 212, a bottom or distal housing 214, and a tip housing 216. Distal housing 214 including an aperture 214 a (see e.g., FIG. 7) defined in a side surface thereof through which is disposed a finger switch 218. Proximal housing 212 and distal housing 214 are releasably coupled to each other, which may facilitate assembly of instrument drive connector 200, and which may facilitate access, repair, and/or replacement of parts housed at least partially therein. Housing assembly 210 may include cantilevered arms, levers, or paddles 211 configured for use in disconnecting instrument drive connector 200 from distal end 64 of housing 60 of instrument drive unit 50 (FIG. 2).

With reference now to FIG. 6, housing assembly 210 supports a first drive assembly 230, a second drive assembly 260, and a third drive assembly 280 for effecting a function of end effector 410 of surgical instrument 100 (FIG. 2). Housing assembly 210 defines a cavity 210 a therein in which at least a portion of the first, second, and third drive assemblies 230, 260, and 280 are disposed. A plate 213 is disposed within cavity 210 a between or at the junction of proximal and distal housings 212 and 214. Plate 213 defines a plurality of openings 213 a-213 c therethrough in which components of first, second, and third drive assemblies 230, 260, and 280 are disposed.

A proximal end portion 220 a of elongated shaft 220 is disposed within a distal end portion 216 a of tip housing 216 and a distal end 214 b of distal housing 214 is pressed distally onto proximal end portion 220 a of elongated shaft 220 to retain elongated shaft 220 securely between distal housing 214 and tip housing 216, thereby keeping the elongated shaft 220 straight and preventing shaft rotation.

Referring now to FIGS. 6-10, first drive assembly 230, also referred to herein as a locking assembly, includes a first input drive coupler 232, a first drive screw 234, a first drive nut 236, and a first drive member or locking link or shaft 238. First input drive coupler 232 is disposed at a proximal end 212 a of proximal housing 212 of housing assembly 210 and is configured to engage an output drive coupler (not shown) of instrument drive unit 50 (FIG. 2). First input drive coupler 232 is configured to mechanically engage a proximal end of first drive screw 234. An aperture 232 a defined through first input drive coupler 232 has a corresponding, non-circular cross-section with the proximal end of first drive screw 234 such that first input drive coupler 232 and first drive screw 234 are keyed to one another, which results in a rotationally fixed connection therebetween. Accordingly, rotation of first input drive coupler 232 results in a corresponding rotation of first drive screw 234.

First drive screw 234 includes a non-threaded proximal body portion 234 a and a threaded distal body portion 234 b, and defines a longitudinal axis “A” extending through a radial center thereof. Rotation of first input drive coupler 232 causes first drive screw 234 to rotate about longitudinal axis “A” in a corresponding direction and rate of rotation. A proximal bearing 231 is disposed about a proximal end of non-threaded proximal body portion 234 a of first drive screw 234, adjacent a portion of proximal housing 212, and a distal bearing 233 is disposed about a distal end of threaded distal body portion 234 b of first drive screw 234 adjacent a portion of distal housing 214. Proximal and distal bearings 231 and 233 permit or facilitate rotation of first drive screw 234 with respect to housing assembly 210 without causing longitudinal movement of first drive screw 234.

First drive nut 236 includes a body 240 having a threaded aperture 241 extending longitudinally through an inner surface 240 a of body 240, which is configured to mechanically engage threaded distal body portion 234 b of first drive screw 234. First drive nut 236 is configured to be positioned on first drive screw 234 in a manner such that rotation of first drive screw 234 causes longitudinal movement of first drive nut 236. In embodiments, first drive nut 236 and first drive screw 234 are threadedly engaged with each other. Moreover, rotation of first input drive coupler 232 in a first direction (e.g., clockwise) causes first drive nut 236 to move in a first longitudinal direction (e.g., proximally) with respect to first drive screw 234, and rotation of first input drive coupler 232 in a second direction (e.g., counter-clockwise) causes first drive nut 236 to move in a second longitudinal direction (e.g., distally) with respect to first drive screw 234.

First drive nut 236 includes a tab or rail 242 extending longitudinally along the outer surface 240 b of body 240, and which is configured to be slidably disposed in a longitudinally extending channel 210 b formed in cavity 210 a of housing assembly 210 (FIG. 8). Rail 242 of first drive nut 236 cooperates with channel 210 b of housing assembly 210 to inhibit or prevent first drive nut 236 from rotating about longitudinal axis “A” as first drive screw 234 is rotated. First drive nut 236 includes a slit 243 defined in outer surface 240 b of the body 240 that is configured for receipt and securement of a proximal end portion of locking link 238. A projection or rod 244 (FIGS. 9A and 9B) extends transversely through slit 243 and locking link 238 to retain locking link 238 within slit 243 of first drive nut 236. First drive nut 236 further includes a tab 246 extending laterally from body 240 of first drive nut 236 (FIG. 7). Tab 246 extends through aperture 214 a formed in housing assembly 210 and into finger switch 218 for manual movement of first drive nut 236 by a clinician (if needed), as described in further detail below.

As illustrated in FIGS. 6 and 10, locking link 238 includes an elongated body 250 having a proximal end portion 250 a and a distal end portion 250 b. Proximal end portion 250 a is securely engaged within slit 243 of first drive nut 236, as described above, such that longitudinal movement of first drive nut 236 causes a corresponding longitudinal movement of locking link 238. Locking link 238 extends distally through housing assembly 210 and elongated shaft 220, such that distal end portion 250 b of elongated body 250 is disposed within elongated shaft 220 and movable between a locking position (FIG. 9A) and a non-locking position (FIG. 9B).

Proximal end portion 250 a of locking link 238 has a laterally extending wing 252 movably disposed within slit 243 of first drive nut 236. Wing 252 of locking link 238 includes a longitudinal slot 252 a formed therein. As described above, rod 244 of first drive nut 236 is disposed within longitudinal slot 252 a of locking link 238 and rides within longitudinal slot 252 a upon proximal or distal longitudinal movement of locking link 238 relative to first drive nut 236.

Longitudinal slot 252 a of locking link 238 has a proximal end surface 252 b and a distal end surface 252 c. As such, when first drive nut 236 is in a distal locking position, as shown in FIG. 9A, rod 244 of first drive nut 236 is engaged with distal end surface 252 c of longitudinal slot 252 a of locking link 238 resisting or preventing locking link 238 from moving in a proximal direction from the distal locking position to a proximal non-locking position. When first drive nut 236 is in the proximal non-locking position, as shown in FIG. 9B, rod 244 of first drive nut 236 is disengaged from distal end surface 252 c of longitudinal slot 252 a of locking link 238 so as to no longer resist locking link 238 from moving in a proximal direction from the distal locking position to the proximal non-locking position.

Distal end portion 250 b of elongated body 250 of locking link 238 includes a switch actuation assembly 254 proximal to an extension 255 disposed at a distalmost end 250 c of elongated body 250 of locking link 238, as will be described in further detail below.

With reference now to FIGS. 6 and 8-11, second drive assembly 260, also referred to herein as an articulation assembly, includes a second input drive coupler 262, a second drive screw 264, a second drive nut 266, and a second drive member or articulation link or shaft 268. Second drive assembly 260 is substantially similar to the first drive assembly 230, and is only described herein to the extent necessary to identify the components thereof and to describe the differences in construction and operation thereof. Second input drive coupler 262 is configured to be detachably, non-rotatably coupled to the second drive screw 264, and includes an aperture 262 a extending longitudinally therethrough, which is configured to mechanically engage and be keyed to a proximal portion of second drive screw 264 which results in a rotationally fixed connection therebetween.

Second drive screw 264 includes a non-threaded proximal body portion 264 a and a threaded distal body portion 264 b and defines a longitudinal axis “B” extending through a radial center thereof. A proximal bearing 261 is disposed about a proximal end of non-threaded proximal body portion 264 a of second drive screw 264, and a distal bearing 263 is disposed about a distal end of threaded distal body portion 264 b of second drive screw 264 to permit or facilitate rotation of second drive screw 264 about longitudinal axis “B” without permitting longitudinal movement of second drive screw 264.

Second drive nut 266 includes a body 270 having a threaded aperture 271 extending longitudinally through an inner surface 270 a of body 270, which is configured to mechanically engage threaded distal body portion 264 b of second drive screw 264. Second drive nut 266 includes a tab or rail 272 extending longitudinally along the outer surface 270 b of body 270, and which is configured to be slidably disposed in a longitudinally extending channel 210 c formed in cavity 210 a of housing assembly 210 (FIG. 8). Second drive nut 266 includes a slit 273 defined in outer surface 270 b of the body 270 that is configured for fixed receipt and securement of a proximal end of articulation link 268. As such, upon rotation of second drive screw 264, second drive nut 266 moves either proximally or distally along second drive screw 264 to effect a corresponding longitudinal movement of articulation link 268.

Articulation link 268 includes an elongated body 274 having a proximal end portion 274 a and a distal end portion 274 b. Proximal end portion 274 is securely engaged within slit 273 of second drive nut 266, as described above. Articulation link 268 extends distally through housing assembly 210 and elongated shaft 220, such that the distal end portion 274 b of the elongated body 274 is disposed within shaft 220. Distal end portion 274 b includes an extension 276, such as a j-hook, that is releasably couplable to end effector 410 (FIG. 2). Accordingly, rotation of second drive input coupler 262 causes a corresponding rotation of second drive screw 264, which in turn, effects a corresponding longitudinal movement of second drive nut 266 and articulation link 268, which in turn, effects articulation of an end effector to actuate, for example, a knife blade or a pair of jaws.

As shown in FIGS. 6, 7, and 10-12, third drive assembly 280, also referred to herein as a firing assembly, includes a proximal shaft 282, a distal shaft 284, a drive rod 286, and a drive shaft 288. Proximal shaft 282 includes a non-threaded shaft body 282 a including a third input drive coupler 290 disposed at a proximal end thereof and a distal gear 292 having a plurality of gear teeth 292 a disposed at a distal end of non-threaded shaft body 282 a. Third input drive coupler 290 and distal gear 292 are non-rotatably secured to shaft body 282 a such that rotation of third input drive coupler 290 results in a corresponding rotation of shaft body 282 a and distal gear 292. A distalmost end 282 b of proximal shaft 282 is secured within a bearing 281 disposed within plate 213 of housing assembly 210 such that proximal shaft 282 will rotate without longitudinal movement.

Distal shaft 284 includes a proximal gear 294 non-rotatably secured to an elongated non-threaded shaft body 284 a. Teeth 292 a of distal gear 292 of proximal shaft 292 is meshingly engaged with teeth 294 a of proximal gear 294 of distal shaft 284 such that rotation of distal gear 292 results in a corresponding rotation of proximal gear 294, which in turn, results in rotation of shaft body 284 a of distal shaft 284. A distal end of shaft body 284 a of distal shaft 284 abuts an inner surface of distal housing 214 such that rotation of distal shaft 284 does not result in axial translation of distal shaft 284.

Proximal gear 294 a defines a central aperture 294 b that is aligned with a threaded channel 284 b defined in shaft body 284 a of distal shaft 284, and extends the entire longitudinal length of distal shaft 284. Drive rod 286 includes a threaded elongated body 286 a and is configured to mechanically engage the threaded channel 284 b of shaft body 284 a of distal shaft 284 in such a manner that rotation of shaft body 284 a causes longitudinal movement of drive rod 286. That is, threaded channel 284 b of shaft body 284 a of distal shaft 284 and threaded elongated body 286 a of drive rod 286 are threadedly engaged with each other. Moreover, rotation of distal shaft 284 in a first direction (e.g., clockwise) causes drive rod 286 to move in a first longitudinal direction (e.g., proximally) with respect to distal shaft 284, and rotation of drive shaft 284 in a second direction (e.g., counter-clockwise) causes drive rod 286 to move in a second longitudinal direction (e.g., distally) with respect to distal shaft 284. Drive rod 286 includes a non-threaded distal end 286 b that is keyed to a recess 288 a defined in a proximal end of drive shaft 288 such that longitudinal movement of drive rod 286 causes a corresponding longitudinal movement of drive shaft 288 to effect a function of end effector 410, such as firing of staple(s) (FIG. 2).

Referring now to FIGS. 13-15, a flexible circuit or flex circuit 300 is disposed within elongated shaft 220 of instrument drive connector 200 and is configured to electrically connect electrical components of instrument drive connector 200 and/or end effector 410 (FIG. 2) to a processor of instrument drive unit 50 and/or medical workstation 1 (FIG. 1). The flex circuit 300 is easily to assemble within instrument drive connector 200 and eliminates the need for discreet, separate wires, ultimately enhancing patient safety and reducing manufacturing costs. Flex circuit 300 extends longitudinally through the elongated shaft 220 and has a proximal end 300 a and a distal end 300 b. Proximal end 300 a of flex circuit 300 is configured for electrical communication with contacts or the like (not shown) provided in proximal housing 212 of instrument drive connector 200. Distal end 300 b of flex circuit 300 terminates at a switch 310 which is oriented in a distal facing direction and configured to be activated upon proper connection of surgical loading unit 400 (FIG. 2) to instrument drive connector 200. Switch 310 communicates with the processor of medical work station 1 (FIG. 1) that surgical loading unit 400 is engaged to, or disengaged with, the elongated shaft 220 of instrument drive connector 200.

Switch 310 is in operative communication with the switch actuation assembly 254 disposed at the distal end portion 250 b of elongated body 250 of locking link 238. As shown in FIGS. 10 and 13-15, switch actuation assembly 254 includes a proximal end portion 254 a that defines an elongated opening 254 b have a coil spring 256 disposed therein. Coil spring 256 is secured within the elongated opening 254 b between a distal end of an inner surface 254 c of the elongated opening 254 b and a projection 257 which projects through the elongated opening 254 b. Switch actuation assembly 254 further includes a distal end portion 254 c including a switch actuating arm 258 that is longitudinally movable between a proximal position and a distal position upon movement of elongated body 250 of locking link 238. Coil spring 256 resiliently biases the switch actuating arm 258 distally so that the arm 258 is distal of switch 310 and maintained in the proximal non-locking position of FIG. 9B, unless held in another different position, as described in further detail below.

With reference now to FIG. 16, in conjunction with FIG. 15, an annular member 320 is also disposed within the elongated shaft 220. Annular member 320 extends from a proximal end 320 a to a distal end 320 b and defines a cylindrical passageway therethrough. Proximal end 320 a includes a first ring 322 and distal end 320 b includes a second ring 324, spaced from the first ring 322 along a longitudinal bar 325 extending along a length of the annular member 320. First ring 322 includes a pair of electrical contacts 326 a and 326 b electrically coupled to switch 310 via wires 328. Electrical contacts 326 a and 326 b are configured to engage corresponding electrical contacts of a surgical loading unit 400, such that switch 310 and annular member 320 are capable of transferring data pertaining to surgical loading unit 400 therebetween. For example, electrical contacts 326 a and 326 b may be configured to couple to a memory (not shown) disposed within surgical loading unit 400, which is configured to store data pertaining to surgical loading unit 400 and to provide said data to flex circuit 300 in response to surgical loading unit 400 being coupled to instrument drive connector 200. Second ring 324 is configured and dimensioned to receive a proximal end of surgical loading unit 400 and to interface with surface features of surgical loading unit 400 so that annular member 320 is rotatable by and with surgical loading unit 400.

Instrument drive connector 200 has a load state, an unload state, and a locked state. The load state allows a surgical loading unit 400 to be freely inserted into instrument drive connector 200. The unload state allows a surgical loading unit 400 to be freely removed from instrument drive connector 200. The unload state requires a clinician to deliberately twist and pull surgical loading unit 400 from instrument drive connector 200 ensuring that at no time surgical loading unit 400 can fall off instrument drive connector 200. In the locked state, a surgical loading unit 400 cannot be either inserted or removed from instrument drive connector 200.

With reference to FIGS. 1, 2, 9A, 9B, and 10, to load surgical loading unit 400 onto instrument drive connector 200, instrument drive connector 200 is switched (either manually or automatically) to a loading state, in which locking link 238 of instrument drive connector 200 is free to move from the distal locking position (FIG. 9A), to the proximal non-locking position (FIG. 9B). In particular, an output drive coupler (not shown) of instrument drive unit 50 operatively engaged with first input drive coupler 232 is manually or automatically activated to drive rotation of first drive screw 234 of instrument drive connector 200 via first input drive coupler 232. Rotation of first drive screw 234 longitudinally moves first drive nut 236 proximally along first drive screw 234 from the distal position, shown in FIG. 9A, to the proximal position, shown in FIG. 9B. As first drive nut 236 moves proximally along first drive screw 234, rod 244 of first drive nut 236 moves longitudinally through longitudinal slot 252 a of locking link 238 to disengage from distal end surface 252 c of longitudinal slot 252 a of locking link 238.

With first drive nut 236 in the proximal position and rod 244 of first drive nut 236 out of engagement with distal end surface 252 c of longitudinal slot 252 a of locking link 238, rod 244 of first drive nut 236 no longer resists proximal longitudinal movement of locking link 238. As such, an application of a force on extension 255 of locking link 238 by a lug (not shown) of surgical loading unit 400, in a proximal direction, effects proximal longitudinal movement of locking link 238 to move locking link 238 from the distal locking position to the proximal non-locking position.

Surgical loading unit 400 is then rotated to position the lug (not shown) of surgical loading unit 400 within inner groove 222 a of distal cap 222 of elongated shaft 220. Upon rotation, the distal resilient bias of locking link 238 causes locking link 238 to move distally relative to elongated shaft 220 to the distal locking position, in which extension 255 of locking link 238 prevents the lug and thus surgical loading unit 400 from rotating out of the enclosed inner groove 222 a. As such, surgical loading unit 400 is lockingly coupled to instrument drive connector 200 and ready for use.

Upon loading surgical loading unit 400, medical work station 1 may perform integrity checks to assure that surgical loading unit 400 was correctly loaded onto instrument drive connector 200. These checks could include, for example, retracting a knife bar and/or ensuring it cannot move in a direction it was not design to move (which would indicate a misload), checking the range of articulation or load links, etc. The integrity checks could be performed before or during attempts to lower surgical instrument 100 into a patient “P”. If medical work station 1 detects a misload, it could lock out slider 11 such that the surgical assembly 10 cannot be inserted into the patient “P”. Instrument drive connector 200 may also enter the unload state and the medical work station 1 would prompt the clinician to reload surgical loading unit 400.

Once surgical loading unit 400 is coupled to instrument drive connector 200, it may be beneficial to prevent inadvertent removal of surgical loading unit 400 from instrument drive connector 200. To prevent this, instrument drive connector 200 may be switched from the load state to the locked state. In some embodiments, it is envisioned that a computer, for example control device 4 may be programmed to automatically activate instrument drive unit 50 to switch instrument drive connector 200 to the locked state upon control device 4 detecting that surgical loading unit 400 is successfully coupled to instrument drive connector 200. For example, upon successful load, medical work station 1 will automatically switch to a locked state when end effector 410 of the surgical loading unit 400 enters an access port (not shown) disposed inside a patient's body or is a predetermined distance from the patient “P”. In some embodiments, a clinician, upon successfully coupling surgical loading unit 400 to instrument drive connector 200, may activate instrument drive unit 50 to switch instrument drive connector 200 to the locked state. By providing medical work station 1 with the ability to selectively lock surgical loading unit 400 with instrument drive connector 200, any possibility of releasing or dropping surgical loading unit 400 is removed.

Upon proper connection of surgical loading unit 400 with instrument drive connector 200, flex circuit 300 automatically transmits the operating parameters stored in a memory (not shown) to the processor. If surgical loading unit 400 is not properly connected to instrument drive connector 200, or the wrong surgical loading unit 400 is connected to instrument drive connector 200, switch 310 of flex circuit 300 will not be activated such that surgical instrument 100 will not be operable to actuate functions of surgical loading unit 400.

To switch instrument drive connector 200 to the locked state, thereby locking surgical loading unit 400 thereto, first drive nut 236 of instrument drive connector 200 is moved to the distal locking position (FIG. 9A). In the distal locking position, first drive nut 236 resists proximal longitudinal movement of locking link 238 from the distal locking position to the proximal non-locking position, in which surgical loading unit 400 may be inadvertently removed from instrument drive connector 200. To move first drive nut 236 to the distal locking position, an output drive coupler (not shown) of instrument drive unit 50 is activated (either manually or automatically) to drive rotation of first drive screw 234 of instrument drive connector 200 via first input drive coupler 232. Rotation of first drive screw 234 longitudinally moves first drive nut 236 distally along first drive screw 234 from the proximal position, shown in FIG. 9B, to the distal position, shown in FIG. 9A. As first drive nut 236 moves distally along first drive screw 234, rod 244 of first drive nut 236 moves longitudinally through longitudinal slot 252 a of locking link 238 and into engagement with distal end surface 252 c of longitudinal slot 252 a of locking link 150.

With first drive nut 236 in the distal position, and rod 244 of first drive nut 236 engaged with distal end surface 252 c of longitudinal slot 252 a of locking link 238, rod 244 of first drive nut 236 resists proximal longitudinal movement of locking link 238. As such, inadvertent application of a force on locking link 238, in a proximal direction will not move locking link 238 out of the distal locking position and into the proximal non-locking position.

To remove surgical loading unit 400 from instrument drive connector 200, instrument drive connector 200 is switched (either manually or automatically) to an unload state, in which locking link 238 is moved back to the proximal non-locking position. In embodiments, the unload state will occur when instrument drive connector 200 is removed from a patient “P” with a used surgical loading unit 400 attached. Once the surgical loading unit 400 is safely above an access port (not shown) or end effector 410 is a predetermined distance from the patient “P”, medical work station 1 will automatically switch the state of instrument drive connector 200. In the unload state, a clinician can remove surgical loading unit 400. Entering the unload state may depend on whether surgical loading unit 400 was fired. In some embodiments, medical work station 1 may be configured to prevent instrument drive connector 200 from entering the unload state if surgical loading unit 400 was not fired, which would require a clinician to manually unload surgical loading unit 400 through a conventional interface, such as interfacing with a component (e.g., a surgeon console, nurse tower, or dedicated button) of medical work station 1. In some embodiments, a clinician may choose to manually switch between the load and unload states through a conventional interface if surgical loading unit 400 did not fire or the wrong surgical loading unit 400 was loaded.

A situation may arise (e.g., an emergency or system default) in which the instrument drive connector 200 is not able to switch from the locked state to the unload state such that surgical loading unit 400 cannot be removed from instrument drive connector 200 via instrument drive unit 50. Accordingly, in embodiments in which the locked state is enforced by the instrument drive unit 50, removing instrument drive unit 50 from the medical work station 1 will allow surgical loading unit 400 to be removed from instrument drive connector 200. In this situation, to remove surgical loading unit 400 from instrument drive connector 200, instrument drive unit 50 is first detached from housing assembly 210 of instrument drive connector 200. A clinician may then manually move finger switch 218 of first drive nut 236 in a proximal direction by applying a threshold amount of force on finger switch 218. It can be appreciated that because first drive nut 236 is threadedly engaged to first drive screw 234, it cannot move therealong without being rotated. However, first drive screw 234 may be axially movable in a proximal direction relative to housing assembly 210 when instrument drive unit 55 is not engaged to housing 210. Accordingly, as a clinician applies a proximally-oriented force on first drive nut 236, first drive screw 234 moves in a proximal direction with first drive nut 236 to allow first drive nut 236 to be manually moved to the proximal non-locking position.

As first drive nut 236 is manually moved in a proximal direction, rod 244 of first drive nut 236 engages proximal end surface 252 b of longitudinal slot 252 a of locking link 238, moving locking link 238 in the proximal direction into the proximal non-locking position. With locking link 238 in the proximal non-locking position, surgical loading unit 400 may be removed by rotating surgical loading unit 400 and then moving surgical loading unit 400 in a distal direction out of distal cap 222 of instrument drive connector 200.

In some embodiments, an array of lights (not shown) may be provided on any or all of the components of robotic arm 2, instrument drive unit 50, instrument drive connector 200 of surgical assembly 10, and/or a surgical robotic cart (not shown) configured for supporting at least one robotic arm 2. These lights may indicate the status of the surgical instrument, for example: the robotic arm is in patient with no errors (ready to retract for exchange of the surgical loading unit); the robotic arm is in the patient with an error (cannot retract the surgical loading unit); or the robotic arm is out of the patient and in an unload state, a locked state, a load state waiting for the surgical loading unit, a load state having a successfully loaded surgical loading unit, or an unloaded state having a misloaded surgical loading unit.

A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the disclosure. Accordingly, other embodiments are within the scope of the following claims. 

What is claimed is:
 1. An instrument drive connector for interconnecting an instrument drive unit and a surgical loading unit including an end effector, wherein the instrument drive connector transmits at least one force from the instrument drive unit to the surgical loading unit to effect a function of the end effector, the instrument drive connector comprising: a housing assembly; an elongated shaft extending distally from the housing assembly, the elongated shaft configured for coupling to a surgical loading unit; and a first drive assembly at least partially disposed within the housing assembly and the elongated shaft, the first drive assembly including: a first drive screw having a proximal end and a distal end; a first input drive coupler non-rotatably coupled to the proximal end of the first drive screw; a first drive nut threadedly engaged with a threaded body portion of the first drive screw and longitudinally movable relative thereto between a distal position and a proximal position in response to rotation of the first drive screw, the first drive nut including a rod; and a locking link including an elongated body having a proximal end portion and a distal end portion, the proximal end portion including a longitudinal slot formed therein, the rod of the first drive nut disposed within the longitudinal slot such that the locking link is movable relative to the first drive nut between a proximal non-locking position in which a surgical loading unit can be inserted or removed from the elongated shaft and a distal locking position in which the locking link is configured to lockingly couple a surgical loading unit to the elongated shaft, and when the first drive nut is in the distal position, the rod of the first drive nut is engaged with a distal end surface of the longitudinal slot such that the locking link is retained in the distal locking position, and when the first drive nut is in the proximal position, the rod is disposed adjacent a proximal end surface of the longitudinal slot such that the locking link is movable to the proximal non-locking position, and the distal end portion including a switch actuating arm, wherein the switching arm is biased such that the locking link is biased towards the distal locking position.
 2. The instrument drive connector of claim 1, wherein a coil spring is disposed in an elongated opening proximal of the switch actuating arm, wherein the coil spring biases the switch actuating arm distally to bias the locking link towards the distal locking position and is movable proximally.
 3. The instrument drive connector of claim 1, further comprising a switch disposed in the elongated shaft.
 4. The instrument drive connector of claim 3, further comprising an annular member disposed in a distal end of the elongated shaft, the annular member including a pair of electrical contacts electrically coupled to the switch.
 5. The instrument drive connector of claim 3, further comprising a flex circuit disposed in the elongated shaft, and wherein the switch is disposed at a distal end of the flex circuit.
 6. The instrument drive connector of claim 5, wherein the flex circuit extends longitudinally through the elongated shaft, the flex circuit including a proximal end configured for electrical communication with a processor.
 7. The instrument drive connector of claim 1, wherein the housing assembly defines an aperture in a side surface thereof, and the first drive nut includes a tab extending through the aperture and into a finger switch for manual movement of the first drive nut.
 8. The instrument drive connector of claim 1, further comprising a second drive assembly including: a second drive screw having a proximal end and a distal end; a second input drive coupler non-rotatably coupled to the proximal end of the second drive screw; a second drive nut threadedly engaged with a threaded body portion of the second drive screw and longitudinally movable relative thereto in response to rotation of the second drive screw; and an articulation link including an elongated body having a proximal end and a distal end, the proximal end fixedly coupled to the second drive nut such that longitudinal translation of the second drive nut causes longitudinal translation of the articulation link.
 9. The instrument drive connector of claim 1, further comprising a third drive assembly including: a proximal shaft including a third input drive coupler non-rotatably secured to a proximal end of the proximal shaft and a distal gear non-rotatably secured to a distal end of the proximal shaft; a distal shaft including a proximal gear non-rotatably secured thereto and meshingly engaged with the distal gear of the proximal shaft; a drive rod including a threaded elongated body engaged with a threaded channel defined in the distal shaft and longitudinally movable relative thereto in response to rotation of the distal shaft; and a drive shaft coupled to a distal end of the drive rod.
 10. A surgical instrument for use with and for selective connection to an instrument drive unit, the surgical instrument comprising: a surgical loading unit including an end effector; and an instrument drive connector including a housing assembly and an elongated shaft, the elongated shaft configured for coupling to the surgical loading unit, and a first drive assembly at least partially disposed within the housing assembly and the elongated shaft, the first drive assembly including: a first drive screw having a proximal end and a distal end; a first input drive coupler non-rotatably coupled to the proximal end of the first drive screw; a first drive nut threadedly engaged with a threaded body portion of the first drive screw and longitudinally movable relative thereto between a distal position and a proximal position in response to rotation of the first drive screw, the first drive nut including a rod; and a locking link including an elongated body having a proximal end portion and a distal end portion, the proximal end portion including a longitudinal slot formed therein, the rod of the first drive nut disposed within the longitudinal slot such that the locking link is movable relative to the first drive nut between a proximal non-locking position in which the surgical loading unit can be inserted or removed from the elongated shaft and a distal locking position in which the locking link is configured to lockingly couple the surgical loading unit to the elongated shaft, and when the first drive nut is in the distal position, the rod of the first drive nut is engaged with a distal end surface of the longitudinal slot such that the locking link is retained in the distal locking position, and when the first drive nut is in the proximal position, the rod is disposed adjacent a proximal end surface of the longitudinal slot such that the locking link is movable to the proximal non-locking position, and the distal end portion including a switch actuating arm, wherein the switching arm is biased such that the locking link is biased towards the distal locking position.
 11. The surgical instrument of claim 10, wherein a coil spring is disposed in an elongated opening proximal of the switch actuating arm, wherein the coil spring biases the switch actuating arm distally to bias the locking link towards the distal locking position and is movable proximally.
 12. The surgical instrument of claim 10, wherein the instrument drive connector further includes a switch disposed in the elongated shaft.
 13. The surgical instrument of claim 12, wherein the instrument drive connector further includes an annular member disposed in a distal end of the elongated shaft, the annular member including a pair of electrical contacts electrically coupled to the switch.
 14. The surgical instrument of claim 12, wherein the instrument drive connector further includes a flex circuit disposed in the elongated shaft, and wherein the switch is disposed at a distal end of the flex circuit.
 15. The surgical instrument of claim 14, wherein the flex circuit extends longitudinally through the elongated shaft of the instrument drive connector, the flex circuit including a proximal end configured for electrical communication with a processor.
 16. The surgical instrument of claim 10, wherein the housing assembly of the instrument drive connector defines an aperture in a side surface thereof, and the first drive nut includes a tab extending through the aperture and into a finger switch for manual movement of the first drive nut.
 17. The surgical instrument of claim 10, wherein the instrument drive connector further includes a second drive assembly, the second drive assembly including: a second drive screw having a proximal end and a distal end; a second input drive coupler non-rotatably coupled to the proximal end of the second drive screw; a second drive nut threadedly engaged with a threaded body portion of the second drive screw and longitudinally movable relative thereto in response to rotation of the second drive screw; and an articulation link including an elongated body having a proximal end and a distal end, the proximal end fixedly coupled to the second drive nut such that longitudinal translation of the second drive nut causes longitudinal translation of the articulation link, and the distal end of the articulation link is releasably coupled to the surgical loading unit to effect articulation of the end effector.
 18. The surgical instrument of claim 10, wherein the instrument drive connector further includes a third drive assembly, the third drive assembly including: a proximal shaft including a third input drive coupler non-rotatably secured to a proximal end of the proximal shaft and a distal gear non-rotatably secured to a distal end of the proximal shaft; a distal shaft including a proximal gear non-rotatably secured thereto and meshingly engaged with the distal gear of the proximal shaft; a drive rod including a threaded elongated body engaged with a threaded channel defined in the distal shaft and longitudinally movable relative thereto in response to rotation of the distal shaft; and a drive shaft coupled to a distal end of the drive rod and longitudinally movable therewith, and a distal end of the drive shaft is in operable communication with the surgical loading unit to effect a function of the end effector. 